Electric-light apparatus



Sept. 1, 1925. 1,552,349

W. DA. RYAN ELECTRIC LIGHT APPARATUS Filed Feb. 20, 1925 ig- 23.

' Invgntofi Walter DARga b9 fiisfl'tlorneg.

particular pattern.

Patented Sept. 1, 1925.

UNlTED STATES PATENT OFFICE.

WALTER DA. RYAN, 0'1? SGHENEGTADY, NEW YORK, ASSIGNOR TO GENERALELECTRIC CGMPANY, A QURPOBATION OF NEW YORK.

ELECTRIG-LIGHT APPARATUS.

Application filed February 20, 1923.

To all whom it may concern Be it known that I, WALTER DA. RYAN, acitizen of the United States, residing at Schenectady, in the county ofSchenectady, State of New York, have invented certain new and usefulImprovements in Electric- Light Apparatus, of which the following is aspecification.

My i1 Vention relates to an improvement in electric light apparatus ofthe type in which an arc lamp having a plurality of anodes is used.

Arc lamps are usually constructed with a single positive electrode and acorresponding negative or cathode electrode. In some cases a pair ofanode electrodes are used but in either case a single crater ismaintained and when are lamps of this type are used in a Searchlight asingle beam is produced. hen a search-light of this type is used in aneffort to locate an object at a distance such as a flying machine, it isoften the case that the machine can dodge the beam, particularly if thebeam is moved to describe a Among the objects of my invention is toprovide an arc lamp in a search light which will produce a series ofbeams which will make it more diiiicult for an object with such anairplane to success fully carry out its dodging operation. It is one ofthe objects of the invention to provide an arc lamp with a series ofanode electrodes on one side of the are. It is another object of myinvention to provide means for causing the arc to pass from one of theanode electrodes to the other in succession, to provide means forcausing the shifting to take place at such a rate as to create theeffect on the eye as though a series of beams were maintained inoperation at the same time to produce an elongated beam which may berotated in order that an object when once located by the beam may befollowed by simply rotating the beam, if the object happens to be movingto one side of the center of the beam. It is also an object of myinvention to produce such a beam in order that when an elongated objectsuch as a war ship is located, the beam may be rotated until the majoraxis of the beam extends parallel or approximately parallel to thelongitudinal axis of the object. I also contemplate providing otherdetails of improvement for increasing Serial No. 620,309.

the efliciency of a device of the above character.

A means for accomplishing the above and other useful ends arehereinafter set forth and claimed.

Referring to the accompanying drawing, Fig. 1 shows the arc lamp inperspective; Fig. 2 is an end view of the lamp; Fig. 3 is a detail ofthe cathode electrode; Fig. 4 shows the lamp associated with a parabolicreflector and so mounted that the anode terminals and the oppositecathode are in the proximity of the focus of the reflector; and Fig. 5is a diagrammatic drawing of the circuits of the lamp and of thecommutator.

Referring more in detail to the drawing, the frame A of the lamp may beof any suitable form. As indicated it is provided with a plate 2 and aplate 3 which plates are held together by the rods 4. The cathodeelectrode 5 on one side of the arc passes through the plate A and isheld insulated from the plate by a washer 6 of any suitable insulatingmaterial. This cathode may be fed by any suitable feeding mechanism. Theanode electrodes 7 8 and 9 are insulated from one another as indicatedin Figs. 2 and 5 and are secured within the rectangular holder 10. Theseanodes may be rigidly secured with respect to the frame as indicated inthe drawing and the frame as a whole moved under the control of a feedmechanism as is commonly done, or the electrodes may be made movablewith respect to the frame and may be fed independently of any movementof the frame. The are lamp as a unit may be secured to the reflector asindicated in Fig. 4. The feeding of the cathode may take place behindthe reflector. Referring to Fig. 5, the conductors 11 and 12 areconnected with any suitable source of power such as a dynamo or battery.Conductor 12 is connected with the cathode 5 on one side of the arc. Onthe other hand, the conductor 11 is connected with a brush 13 whichlatter is in electric engagement with a ring 14. This ring is inelectric connection with the seg ment 15 of the commutator. Associatedwith the commutator are three other brushes 16, 17 and 18. Each of thesebrushes is connected as indicated in Fig. 5 with one .Of the anodeelectrodes on the same side of the arc. The commutator may be driven byany suitable mechanism so that the segment 15 is caused to engage thebrushes 16, 17 and 18 one at a time. The result is that the anodes arethrown in circuit with the mains 11 and 12 one at a time and, therefore,the arc is caused to travel from one anode to another on one side of thearc while the other side of the arc rests perma ncntly on the cathode 5.With this arrangement it will be seen that I provide three arcs, onebetween the cathode 5 and the anode 7, another with the anode 8 and athird with the anode 9, Inasn' uch as these arcs shift with respect tothe focus of the reflector, each arc causes a separate d distinct beamto be projected from the rei'l ctor B. However, only one beam isactually in existence at a time but the commu tator is caused to rotatesuch a speed as to produce the alternation of the beams at such a rateas to leave an impression on the eye as though they all persisted at thesame time. lVith this arrangement, therefore, the search-light will ineliect cover a much larger region and consequently the operation oflocating an object can be carried out much more effectively and muchmore rapidly by minimizing the possibility of the object dodging thesearcher.

hat 1 claim as new and eesire to secure by Letters Patent of the UnitedStates, is,-

In a searchlight, an arc lamp having a series of anode electrodes acommon cathode and a distributor, and a pair of conducting leads forconnecting the lamp with a source of current, one of said leads beingconnected to the cathode, said distributor being interposed between theother lead and the anodes whereby said anodes may be connected one at atime with the last mentioned lead and an are formed between the cathodeand the anodes in succession.

In witness whereof I have hereunto set my hand this 19th day ofFebruary, 1923.

lVALTER DA. RYAN.

